[Federal Register Volume 59, Number 213 (Friday, November 4, 1994)]
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From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-26983]


  Federal Register / Vol. 59, No. 213 / Friday, November 4, 1994 /
  
[[Page Unknown]]

[Federal Register: November 4, 1994]


                                                   VOL. 59, NO. 213

                                           Friday, November 4, 1994

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-ANE-26; Amendment 39-9062; AD 94-22-12]

 

Airworthiness Directives; Hamilton Standard 14RF, 247F, 14SF, and 
P6/5500/F Series Propellers

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Hamilton Standard 14RF, 247F, 14SF, and 6/5500/F 
(formerly Hamilton Standard/British Aerospace 6/5500/F) series 
propellers, that currently requires initial and repetitive inspections 
of the propeller control unit (PCU) servo ballscrew internal spline 
(BIS) teeth for wear, and replacement, if necessary, of PCU servo BIS 
assemblies. This amendment increases the repetitive inspection interval 
from 500 to 1,500 hours time in service (TIS) since last inspection for 
propellers that have a ballscrew quill damper installed. This amendment 
is prompted by the availability of improved hardware that restricts 
quill motion and enhances the lubrication of the BIS and significantly 
reduces BIS wear. The actions specified by this AD are intended to 
prevent inability to control the propeller blade angle due to tooth 
wear in the PCU servo BIS assembly.

DATES: Effective December 5, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 5, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from Hamilton Standard, One Hamilton Road, Windsor Locks, CT 
06096-1010. This information may be examined at the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, 12 New England Executive Park, Burlington, MA 01803-5299; or 
at the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Frank Walsh, Aerospace Engineer, 
Boston Aircraft Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; 
telephone (617) 238-7158, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 93-16-02, 
Amendment 39-8659 (58 FR 44441, August 23, 1993), which is applicable 
to Hamilton Standard 14RF, 247F, 14SF, and 6/5500/F (formerly Hamilton 
Standard/British Aerospace 6/5500/F) series propellers, was published 
in the Federal Register on May 27, 1994 (59 FR 27510). That action 
proposed to increase the repetitive inspection interval from 500 to 
1,500 hours time in service (TIS) since last inspection for propellers 
that have a ballscrew quill damper installed.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Seven commenters concur with the rule as proposed.
    One commenter concurs with the proposal to extend the repetitive 
inspection interval from 500 to 1,500 hours TIS, but also states that 
paragraph (a)(5) of the NPRM requires inspection at 1,500 hours TIS if 
a damper is installed, but previously ``new'' PCU's were not required 
to be inspected until 1,800 hours TIS since new. The commenter further 
states that this interval is not consistent since it is a decrease of 
300 hours with the improved hardware, and recommends the interval to be 
extended to 1,800 hours TIS for new PCU's. The FAA concurs and has 
revised this final rule accordingly.
    The commenter also recommends the following changes to Appendix 1 
of the NPRM:
    The commenter states that the date of the damper installation 
should not be required since those receiving a ``new'' PCU or one from 
a repair station where the damper was installed may not have access to 
the actual installation date. What should be required is an answer to 
the question, ``Damper installed?'' (answer either ``Yes'' or ``No''), 
and if ``Yes'', and the indication of whether it was installed ``at 
this inspection'' or ``previously.'' The FAA concurs and has revised 
this final rule accordingly.
    The commenter states that the requirement to list the aircraft 
model is not required provided the PCU part number is complete with the 
dash or ``A'' number. The FAA concurs and has revised this final rule 
accordingly.
    The commenter states that blanks are not needed for the items 
``Estimated Time on PCU'' and ``Actual Time on PCU.'' What is needed is 
an indication as to which one of those statements applies to the 
following: ``Time Since New (hours)'' and ``Time Since Last Ballscrew 
Inspection/Repair (hours).'' The FAA concurs and has revised this final 
rule accordingly.
    The commenter states that there is no requirement to indicate (a 
reminder to complete) completion of the ``pull check'' of the PCU quill 
after it is reinstalled. The FAA concurs and has added this item to 
Appendix 1 of this final rule.
    Two commenters indicate that the installation of the damper had 
merit and should reduce the PCU's vulnerability to wear. However, the 
commenters believe that the inspection interval should not be extended 
to 1,500 hours TIS for the following reasons:
    The first commenter states that the root cause or single reason for 
the ballscrew internal spline wear has not been identified. The 
Original Equipment Manufacturer (OEM) bench test of the modified 
ballscrew internal spline quill installation does not demonstrate a 
test that duplicates actual operation; e.g., there is retaining wire 
wear due to axial preload from the damper. Also, currently there is 
inadequate scientific basis for reliance on the test data as there is 
insufficient field experience data.
    The second commenter also states that the specific cause of wear 
has not been positively identified. The proposed modification does not 
correct the negative failure modes in the PCU should a wear induced 
failure occur. Finally, this commenter expresses concern that the field 
data used to justify the increased inspection interval is being 
collected only from a small percentage of units in operation.
    The FAA does not concur with these comments. The FAA has researched 
these issues and reviewed the data from numerous tests and 
investigations that have been conducted to determine the cause of 
extreme wear when it occurs on a very small number of splines in 
service. The FAA has determined that by these tests and investigations 
a number of factors contribute to how or if the spline joint will wear. 
These factors include:
    Magnitude and direction of vibratory environment.
    How well the spline joint is lubricated.
    Motion of elements within the joint due to stack up of clearances.
    Thickness of chrome plating on spline teeth.
    The FAA has therefore determined that there is no single factor for 
wear of this complex joint. However, the major contributors of the 
listed factors have been found to be lubrication and axial motion. 
Laboratory tests and controlled field service data has proven the 
damper reduces the wear factor by well over 20 times the rate before 
its installation.
    The retaining wire wear is not a phenomenon associated with the 
damper introduction. The retaining wires generally show some degree of 
marking (mainly dents in the wire) from the flat end of the ballscrew 
spline teeth bearing on the round wire. This marking occurs on 
retaining wires on PCU's with and without dampers installed. After an 
initial ``Seating'' of the parts, the retaining wire continues to 
operate without distress.
    Currently, the FAA has reported data from high time controlled 
field service units in multiple model installations to have accumulated 
over 2,138 hours TIS with the same damper installed. In addition, the 
damper modification has been available to operators since January 1, 
1994. The manufacturer has shipped over 2,800 modification kits and has 
conservatively estimated that over 300,000 hours of field time has been 
logged by operators with the modification installed.
    Based on the investigative reports, satisfactory field inspection 
data, and improved wear factors resulting from the installed damper 
modification, the FAA has determined that a negative failure mode 
should not occur within the new inspection interval of 1,500 hours TIS. 
The FAA has therefore adopted the inspection interval stated in the 
NPRM.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 2,506 propellers of the affected design in 
the worldwide fleet. The FAA estimates that 1,150 propellers installed 
on aircraft of U.S. registry will be affected by this AD, that it will 
take approximately 1.5 work hours per propeller to accomplish the 
required actions, and that the average labor rate is $55 per work hour. 
Based on these figures, and on the average utilization rate of 2,000 
hours TIS per year equating to 4 inspections, the total cost impact of 
the current AD per year on U.S. operators is estimated to be $379,500. 
However, based on an average utilization rate of 2,000 hours TIS per 
year, this superseding AD will eliminate 2.7 inspections per year per 
propeller, resulting in an approximate yearly cost savings to U.S. 
operators of $256,163.
    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air Transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-8659 (58 FR 
44441, August 23, 1993) and by adding a new airworthiness directive, 
Amendment 39-9062, to read as follows:

94-22-12 Hamilton Standard: Amendment 39-9062. Docket 94-ANE-26. 
Supersedes AD 93-16-02, Amendment 39-8659.

    Applicability: Hamilton Standard Models 14RF-9, 14RF-19, 14RF-
21, and 14RF-23; 247F-1; 14SF-5, 14SF-7, 14SF-11, 14SFL11, 14SF-15, 
14SF-17, 14SF-19, 14SF-23; and 6/5500/F propellers installed on but 
not limited to Embraer EMB-120 and EMB-120RT; SAAB-SCANIA SF340B; 
Aerospatiale ATR42-100, ATR42-300, ATR42-320, ATR72, ATR72-210; 
DeHavilland DHC-8-100 series, DHC-8-300; Construcciones Aeronauticas 
SA (CASA) CN-235 and CN-235-100; Canadair CL215T and CL415; and 
British Aerospace ATP airplanes.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the inability to control the propeller blade angle 
due to tooth wear in the propeller control unit (PCU) servo 
ballscrew internal spline (BIS) assembly, accomplish the following:
    (a) Inspect the PCU servo BIS assembly for tooth wear in 
accordance with the Accomplishment Instructions of the following 
Hamilton Standard Alert Service Bulletins (ASB), all dated April 7, 
1994, as applicable: No. 14RF-9-61-A53, Revision 5; No. 14RF-19-61-
A25, Revision 4; No. 14RF-21-61-A38, Revision 4; No. 247F-61-A3, 
Revision 3; No. 14SF-61-A59, Revision 4; and No. 6/5500/F-61-A11, 
Revision 4; as follows:
    (1) For a PCU with unknown time in service (TIS), and unknown 
TIS since the last inspection, on the effective date of this 
airworthiness directive (AD), and that does not have a ballscrew 
quill damper installed, inspect within 200 hours TIS after the 
effective date of this AD.
    (2) For a PCU with 1,800 or more hours TIS or unknown TIS on the 
effective date of this AD, and either has not been inspected, or has 
been inspected more than 500 hours prior to the effective date of 
this AD, in accordance with the applicable Hamilton Standard ASB 
listed in paragraph (a) of this AD; and that does not have a 
ballscrew quill damper installed; inspect within 200 hours TIS after 
the effective date of this AD.
    (3) For a PCU with 1,800 or more hours TIS or unknown TIS on the 
effective date of this AD, and that has been inspected within the 
previous 500 hours TIS in accordance with the applicable Hamilton 
Standard ASB listed in paragraph (a) of this AD, and that does not 
have a ballscrew quill damper installed, inspect within 500 hours 
TIS since the last inspection in accordance with the applicable 
Hamilton Standard ASB listed in paragraph (a) of this AD.
    (4) For a PCU with less than 1,800 hours TIS on the effective 
date of this AD, and that does not have a ballscrew quill damper 
installed, inspect prior to accumulating 1,800 hours TIS, or within 
300 hours TIS after the effective date of this AD, whichever occurs 
later.
    (5) For a PCU that has a ballscrew quill damper installed in 
accordance with the following applicable Hamilton Standard Service 
Bulletins (SB), or previous revisions: No. 14SF-61-67, Revision 2, 
dated September 27, 1994; No. 14RF-9-61-61, Revision 1, dated 
September 27, 1994; No. 14RF-19-61-29, Revision 2, dated September 
27, 1994; No. 14RF-21-61-48, Revision 2, dated September 27, 1994; 
No. 247F-61-6, Revision 2, dated September 27, 1994; and No. 6/5500/
F-61-19, Revision 2, dated September 27, 1994; inspect within 1,500 
hours TIS since installation of the ballscrew quill damper.
    (6) Thereafter, inspect at intervals described as follows:
    (i) For propellers that have a ballscrew quill damper installed 
in accordance with the applicable Hamilton Standard SB listed in 
paragraph (a)(5) of this AD, or previous revisions, inspect at 
intervals not to exceed 1,500 hours TIS since the last inspection 
required by this AD.
    (ii) For propellers that do not have a ballscrew quill damper 
installed in accordance with the applicable Hamilton Standard SB 
listed in paragraph (a)(5) of this AD, inspect at intervals not to 
exceed 500 hours TIS since the last inspection required by this AD.
    (7) If PCU servo BIS teeth are worn beyond the limits specified 
in the Accomplishment Instructions of the applicable ASB's listed in 
paragraph (a) of this AD, prior to further flight, replace the PCU 
with a serviceable assembly in accordance with the Accomplishment 
Instructions of the applicable ASB's listed in paragraph (a) of this 
AD, and thereafter reinspect in accordance with paragraphs (a)(6) 
and (a)(7) of this AD.
    (b) Report the results of the initial and repetitive inspections 
required by paragraph (a) of this AD by utilizing Appendix 1, 
``Ballscrew Inspection Data,'' within 7 days of the inspection to 
the Manager, Boston Aircraft Certification Office, Engine and 
Propeller Directorate, Aircraft Certification Service, FAA, 12 New 
England Executive Park, Burlington, MA 01803-5299; fax (617) 238-
7199. The reporting requirements of this AD terminate on December 
31, 1995. Information collection requirements contained in this 
regulation have been approved by the Office of Management and Budget 
(OMB) under the provision of the Paperwork Reduction Act of 1980 (44 
U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-
0056.

Appendix 1--Ballscrew Inspection Data

    The following information must be reported and sent as soon as 
possible but no later than 7 days after inspection to: Manager, 
Boston Aircraft Certification Office, Engine and Propeller 
Directorate, Aircraft Certification Service, Federal Aviation 
Administration, 12 New England Executive Park, Burlington, MA 01803-
5299, Fax: (617) 238-7199.

Operator/Repair Station------------------------------------------------

Date of Inspection-----------------------------------------------------

PCU Part Number--------------------------------------------------------
PCU Serial Number------------------------------------------------------

Date Damper Installed--------------------------------------------------

Damper Installed (please circle one): YES    NO

If ``YES,'' please circle one: This inspection    Previously

Aircraft Serial Number-------------------------------------------------

Position (please check one): Left Engine______ Right Engine______

PCU Times (please circle one): Estimated    Actual

Time Since New (Hours)-------------------------------------------------

Time Since Last Ballscrew Inspection/Repair (Hours)______

Inspection (please check one): Accepted______ *Rejected______

    *Please indicate in comments if unit was rejected as part of the 
functional check.

No. of left side teeth with steps______

No. of right side teeth with steps______

Comments:--------------------------------------------------------------

Ballscrew Quill Pull Check Completed (please circle one): YES    NO

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Boston Aircraft Certification 
Office. The request should be forwarded through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Boston Aircraft Certification Office.

    Note: Information concerning the existence of approved 
alternative method of compliance with this AD, if any, may be 
obtained from the Boston Aircraft Certification Office.

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the aircraft to a location where 
the requirements of this AD can be accomplished.
    (e) The requirements of this AD shall be done in accordance with 
the following Hamilton Standard service documents:

----------------------------------------------------------------------------------------------------------------
                     Document No.                          Pages       Revision                 Date            
----------------------------------------------------------------------------------------------------------------
ASB No. 14RF-9-61-A53.................................            1  5............  April 7, 1994.              
                                                                2-7  4............  March 1, 1994.              
                                                                  8  3............  July 28, 1993.              
                                                                  9  5............  April 7, 1994.              
                                                              10-12  4............  March 1, 1994.              
                                                                 13  5............  April 7, 1994.              
                                                              14-20  4............  March 1, 1994.              
                                                                 21  5............  April 7, 1994.              
    Total pages: 21                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
SB No. 14RF-9-61-61...................................          1-2  1............  September 27, 1994.         
                                                               3-10  Original.....  December 9, 1993.           
                                                                 11  1............  September 27, 1994.         
                                                              12-14  Original.....  December 9, 1993.           
    Total pages: 14                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
ASB No. 14RF-19-61-A25................................            1  4............  April 7, 1994.              
                                                                2-7  3............  March 1, 1994.              
                                                                  8  2............  July 28, 1993.              
                                                                  9  4............  April 7, 1994.              
                                                                 10  3............  March 1, 1994.              
                                                                 11  4............  April 7, 1994.              
                                                              12-20  3............  March 1, 1994.              
                                                                 21  4............  April 7, 1994.              
    Total pages: 21                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
SB No. 14RF-19-61-29..................................            1  2............  September 27, 1994.         
                                                                  2  1............  May 6, 1994.                
                                                               3-10  Original.....  December 9, 1993.           
                                                                 11  2............  September 27, 1994.         
                                                              12-13  Original.....  December 9, 1993.           
                                                                 14  1............  May 6, 1994.                
    Total pages: 14                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
ASB No. 14RF-21-61-A38................................            1  4............  April 7, 1994.              
                                                                2-7  3............  March 1, 1994.              
                                                                  8  2............  July 28, 1993.              
                                                               9-10  4............  April 4, 1994.              
                                                              11-20  3............  March 1, 1994.              
                                                                 21  4............  April 7, 1994.              
    Total pages: 21                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
SB No. 14RF-21-61-48..................................          1-4  2............  September 27, 1994.         
                                                               5-10  Original.....  December 9, 1993.           
                                                                 11  2............  September 27, 1994.         
                                                              12-13  Original.....  December 9, 1993.           
                                                                 14  1............  May 6, 1994.                
    Total pages: 14                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
ASB No. 247F-61-A3....................................            1  3............  April 7, 1994.              
                                                                2-7  2............  March 1, 1994.              
                                                                  8  1............  July 28, 1993.              
                                                               9-10  3............  April 7, 1994.              
                                                              11-19  2............  March 1, 1994.              
                                                                 20  3............  April 7, 1994.              
    Total pages: 20                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
SB No. 247F-61-6......................................          1-4  2............  September 27, 1994.         
                                                               5-10  Original.....  December 9, 1993.           
                                                                 11  2............  September 27, 1994.         
                                                              12-13  Original.....  December 9, 1993.           
                                                                 14  1............  May 6, 1994.                
    Total pages: 14                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
ASB No. 14SF-61-A59...................................            1  4............  April 7, 1994.              
                                                                2-7  3............  March 1, 1994.              
                                                                  8  2............  July 28, 1993.              
                                                               9-10  4............  April 7, 1994.              
                                                              11-20  3............  March 1, 1994.              
                                                                 21  4............  April 7, 1994.              
    Total pages: 21                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
SB No. 14SF-61-67.....................................            1  2............  September 27, 1994.         
                                                                  2  1............  May 6, 1994.                
                                                                3-9  Original.....  December 9, 1993.           
                                                                 10  1............  May 6, 1994.                
                                                                 11  Original.....  December 9, 1993.           
                                                                 12  2............  September 27, 1994.         
                                                              13-15  Original.....  December 9, 1993.           
                                                                 16  1............  May 6, 1994.                
    Total pages: 16                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
ASB No. 6/5500/F-61-A11...............................            1  4............  April 7, 1994.              
                                                                2-9  3............  March 1, 1994.              
                                                              10-11  4............  April 7, 1994.              
                                                                 12  2............  July 28, 1993.              
                                                                 13  3............  March 1, 1994.              
                                                                 14  2............  July 28, 1993.              
                                                              15-20  3............  March 1, 1994.              
                                                                 21  4............  April 7, 1994.              
    Total pages: 21                                                                                             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                                
SB No. 6/5500/F-61-19.................................            1  2............  September 27, 1994.         
                                                                  2  1............  May 6, 1994.                
                                                               3-10  Original.....  December 6, 1993.           
                                                                 11  2............  September 27, 1994.         
                                                                 12  Original.....  December 6, 1993.           
                                                              13-14  1............  May 6, 1994.                
    Total pages: 14                                                                                             
----------------------------------------------------------------------------------------------------------------

This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Hamilton Standard, One Hamilton 
Road, Windsor Locks, CT 06096-1010. Copies may be inspected at the 
FAA, New England Region, Office of the Assistant Chief Counsel, 12 
New England Executive Park, Burlington, MA; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (f) This amendment becomes effective on December 5, 1994.

    Issued in Burlington, Massachusetts, on October 26, 1994.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 94-26983 Filed 11-3-94; 8:45 am]
BILLING CODE 4910-13-P